drm/rockchip: dw_hdmi: introduce the pclk for grf

For RK3399's GRF module, if we want to operate the graphic related grf
registers, we need to enable the pclk_vio_grf which supply power for VIO
GRF IOs, so it's better to introduce an optional grf clock in driver.

Signed-off-by: Yakir Yang <ykk@rock-chips.com>
Signed-off-by: Mark Yao <mark.yao@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>

diff --git a/Documentation/devicetree/bindings/display/rockchip/dw_hdmi-rockchip.txt b/Documentation/devicetree/bindings/display/rockchip/dw_hdmi-rockchip.txt
index 122d4e8..fad8b76 100644 (file)
--- a/Documentation/devicetree/bindings/display/rockchip/dw_hdmi-rockchip.txt
+++ b/Documentation/devicetree/bindings/display/rockchip/dw_hdmi-rockchip.txt
@@ -32,6 +32,7 @@ Optional properties
   I2C master controller.
 - clock-names: See dw_hdmi.txt. The "cec" clock is optional.
 - clock-names: May contain "cec" as defined in dw_hdmi.txt.
+- clock-names: May contain "grf", power for grf io.
 - clock-names: May contain "vpll", external clock for some hdmi phy.
 
 Example:

diff --git a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
index c00d7e2..ccd5d59 100644 (file)
--- a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
+++ b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
@@ -47,6 +47,7 @@ struct rockchip_hdmi {
        struct drm_encoder encoder;
        const struct rockchip_hdmi_chip_data *chip_data;
        struct clk *vpll_clk;
+       struct clk *grf_clk;
 };
 
 #define to_rockchip_hdmi(x)    container_of(x, struct rockchip_hdmi, x)
@@ -181,6 +182,16 @@ static int rockchip_hdmi_parse_dt(struct rockchip_hdmi *hdmi)
                return PTR_ERR(hdmi->vpll_clk);
        }
 
+       hdmi->grf_clk = devm_clk_get(hdmi->dev, "grf");
+       if (PTR_ERR(hdmi->grf_clk) == -ENOENT) {
+               hdmi->grf_clk = NULL;
+       } else if (PTR_ERR(hdmi->grf_clk) == -EPROBE_DEFER) {
+               return -EPROBE_DEFER;
+       } else if (IS_ERR(hdmi->grf_clk)) {
+               dev_err(hdmi->dev, "failed to get grf clock\n");
+               return PTR_ERR(hdmi->grf_clk);
+       }
+
        ret = clk_prepare_enable(hdmi->vpll_clk);
        if (ret) {
                dev_err(hdmi->dev, "Failed to enable HDMI vpll: %d\n", ret);
@@ -246,10 +257,17 @@ static void dw_hdmi_rockchip_encoder_enable(struct drm_encoder *encoder)
        else
                val = hdmi->chip_data->lcdsel_big;
 
+       ret = clk_prepare_enable(hdmi->grf_clk);
+       if (ret < 0) {
+               dev_err(hdmi->dev, "failed to enable grfclk %d\n", ret);
+               return;
+       }
+
        ret = regmap_write(hdmi->regmap, hdmi->chip_data->lcdsel_grf_reg, val);
        if (ret != 0)
                dev_err(hdmi->dev, "Could not write to GRF: %d\n", ret);
 
+       clk_disable_unprepare(hdmi->grf_clk);
        dev_dbg(hdmi->dev, "vop %s output to hdmi\n",
                ret ? "LIT" : "BIG");
 }